Rail anchor

ABSTRACT

A one-piece rail anchor of substantially U-shaped cross section which is substantially maintained throughout the entire profile having an improved bearing surface configuration which provides an increased holding capacity.

United States Patent 11 1 1111 3,837,572 Van Sant Sept. 24, 1974 [54] RAIL ANCHOR 1,163,172 12 1915 Preston 238/321 l,382,335 6/l92l Wolhaupter 238/32l [75] Inventor l Sam/Colorado 1,728,188 9/1929 Natale 238/330 p 00' 1,746,820 2/1930 COOk 238/330 [73] Assigneez c x g' a a a :pua 3,102,690 9/1963 Fee 238/327 Colo. Primary ExaminerM. Henson Wood, Jr. [22] 1973 Assistant ExaminerRichard A. Bertsch 21 Appl. No.: 324,815

52 us. (:1. 238/315 [57] ABSTRACT [51] Int. Cl E01b 13/02 A ne-piece rail anchor of substantially U-shaped Fleld of Search 238/304, 3 cross section which is substantially maintained 29/482 throughout the entire profile having an improved bearing surface configuration which provides an in- [56] erence Cited creased holding capacity.

UNITED STATES PATENTS 1,139,391 5/1915 Wolhaupter 238/324 6Cla'ms4D'awmg F'gures RAIL ANCHOR This invention relates to rail anchors and in particu' lar to the one-piece type of rail anchor used for the purpose of preventing longitudinal creep in railroad rails.

Such one-piece anchors are formed from a single piece of rectangular bar stock. One end of the anchor has a hook-shaped portion adapted to grip the top and bottom surfaces of the base of the rail flange on one side of the rail. The other end of the anchor is locked against the edge portion of the opposite rail flange. The central portion of the anchor is usually bowed so that the bottom side of the rail flange straddles two bearing pads, one at each end of the anchor and whereby the bowed portion also abuts a vertical portion of a crosstie at a location below the base of the rail.

Heretofore, one-piece rail anchors of the general type described herein have certain shortcomings, including that of limited holding ability, tilting under load, distortion of tie fibers, gouging or blemishing of the base of the rail, insufficient tie-anchor and railanchor bearing relationship, and a low re-application potential.

The present invention is directed to such one-piece rail anchors and is constructed so as to improve the anchor from the shortcomings noted above. The proposed anchor is constructed from a rectangular piece of bar stock formed into a U-shaped cross section which extends throughout the entire profile of the anchor.

The principal object of the present invention is to provide an improved one-piece rail anchor which provides an increased holding capacity than heretofore achieved in anchors of this type by the unique bearing pad surface which employs a plurality of recesses.

Another object is to construct an anchor of substantially U-shaped cross section throughout, having adequate reserve strength to offset instantaneous peak thermal and dynamic forces occurring in the track.

Still another object is to provide an anchor having continual deep rectangular section throughout the base portion and continual wide rectangular section throughout the anchor to thereby maximize the tieanchor and rail-anchor bearing area relationships, respectively.

Still another object is to provide an anchor having wide rail bearing surfaces to maximize the stability of the anchor to resist the overturning moment of the piece under longitudinal load applications of the rail.

Another object is to provide an anchor having a rectangular profile which in reaction with the tie minimizes the moment arm thereby reducing the overturning effect of the anchor.

Other objects and advantages of the instant invention will be readily apparent from the following specification and drawings wherein:

FIG. 1 is a side view of the rail anchor in its applied position on the base portion of a railroad rail, shown in dotted lines;

FIG. 2 is a partial section view of the anchor taken along lines 22 of FIG. 1;

FIG. 3 is a section taken along line 3-3 of FIG. 1;

FIG. 4 is a section taken along line 4-4 of FIG. 1.

Referring to the drawing, and in particular FIG. 1 and 2, a one-piece rail anchor, generally indicated at 1, is shown engaging the base portion 2 of a rail 4, in the usual manner. The rail 4 is affixed to an underlying crosstie, not shown, forming a part of the road bed, whereby a metal tie plate, also not shown, is normally interposed between the top surface of the crosstie and the base portion of the rail.

The anchor 1 is formed from rectangular steel bar stock which is shaped into a U-shaped channel, as clearly shown in FIG. 3 and 4. The base 6 of the channel has parallel integral legs or flanges 8 and 10 extending therefrom at right angles to said base whereby a cross section of the anchor at any point along its length or external surface will be substantially of U-shaped configuration.

Anchor 1 is formed in a manner whereby one end is bent into a hook portion 16 to provide an upper jaw 20 and a lower jaw 18. Jaws 20, 18 have bearing pads 22,24, respectively, opposing each other whereby flange 14 may be positioned between the said bearing pads. In such position, bearing pad 22 is in resilient gripping engagement with the upper portion of rail flange 14 and bearing pad 24 is in similar gripping engagement with the lower portion of said flange.

From hook portion 16, the anchor 1 extends beneath the rail base 2 to its other end 26 which is provided with a locking shoulder 28 protruding therefrom which engages the vertical edge 30 of flange 12, as clearly shown in FIG. 1. In proximity to locking shoulder 28 is an end bearing pad surface 32 which is on the same plane as bearing surface 24 located on the hook portion 16 when the anchor is in its applied position. Anchor 1 has a downwardly bowed section, generally indicates as 34, between the bearing surfaces 24,32. The bowed portion 34 is adapted to abut against the side face of a cross tie, not shown, in a position to maximize the tieanchor surface relationship. It is noted that the upper jaw 20 on hook portion 16 bears upon the top surface of flange 14 in a manner whereby the bearing surface 22 is positioned somewhat inwardly with respect to the center of the rail 4 than that of bearing surface 24. Upon application, driving the jaws 18,20 on to the rail flange 14 to their desired position effects a turning motion to the anchor about bearing pad 24 whereby shoulder 28, on the opposite end of the anchor, is locked into gripping engagement with the edge 30 of flange 12. The leading edge 21 of upper jaw 20 has a rounded protile, as shown, to minimize damage to flange 14 when the anchor is being applied. The flexing of the hook portion 16 when the anchor is applied to the rail thereby confines the bearing pads into a final position whereby the anchor is resiliently gripped to the rail and is in contact with the rail at the respective bearing pad surfaces 22,24 and 32.

The recesses 36 in bearing pad 24 extend toward the throat 17 to a location where, upon applying the anchor, the leading edge 19 of flange 14 does not come in direct contact with recesses 36 of bearing pad 24. Such positioning is accomplished since the rail base 2 is offset with respect to the bearing pads 32,24 a distance equal to the height of shoulder 28. When flange l2 and its edge 30 pass over the shoulder 28, the base portion of the rail will then be in contact with both aligned pads 24,32 in the applied position of the anchor.

Since the top side of flange 12 and 14 is tapered downward with respect to the base 2, the flange is similar to a wedge when the anchor is placed on the rail. The wedge thus spreads the hook portion to securely hold flange 14 between upper and lower bearing pads 22, 24. The opposite edge 30 of flange 12 will then snap over shoulder 28 and bearing pad 32 will be urged against the bottom portion of the base portion 2 of flange 12, as shown. The resilient action of the hook as the anchor is applied to the rail will be confined after the shoulder 28 snaps over lateral edge 30 of flange 12 to thereby position the anchor on the rail.

With reference to F IG. 2 and 3, bearing pad surfaces 22, 24 and 32 are of rectangular configuration since they are formed on the base 6 of the U-shaped channel of which the anchor is fabricated. The cross-sectional configuration of the anchor taken along any location of its profile is substantially the same and this crosssectional integrity enhances the stability of the anchor. Any deviation from a substantially U-shaped configuration would, obviously, reduce the contact area and reduce the stability of the anchor. Such utilization of a maximum bearing area in contact with the rail flange allows more surface interaction to be achieved between the rail flange and anchor.

Then, to enhance the gripping capacity of the anchor, each bearing pad surface has recesses or dimples 36 which are impressed into said surface, when the anchor is heated to a temperature to allow hot forming of the anchor during its fabrication. The recesses 36 are formed in the bearing pad surface in a manner to preserve a substantially smooth surface on said pad. Any previous method of increasing the interaction between the rail flange and anchor as by knurling, serrating or corrugating the bearing pad surface only lends itself to damage of the surface of the rail flange, which is detrimental.

Although the recesses or dimples 36 in the preferred embodiment show a plurality of circular recesses, it is understood that such recesses could be of other configuration such as linear, rectangular, diamond, or of other forms, all of which are within the scope and intent of the generic term of recesses. Additionally, such recesses may be of various depth, or intensity, all of which would provide the interaction between the rail flange surface and bearing pad surface to thereby enhance the gripping capacity of the anchor, as described herein.

However, because of the contact between the bearing pad surface and rail flange, the recesses 36 improve the functional gripping power of the anchor. Such gripping capacity thus enhances the ability of the anchor to further retard the longitudinal creep of the rail relative thereto, and in addition, reduces the tendency of the anchor to become dislodged or distorted. Such recesses form an interaction between the two surfaces, which is not detrimental to either, but which greatly improves the gripping capacity and functional co-operation between the bearing pad surface and its respective rail flange surface.

Commonly, the rail material as fabricated and used is less hard than the material of which the rail anchor is constructed. Therefore, the common result of the application of the anchoris to gouge the surface of the rail flange. In the instant anchor, the bearing pad surface permits the less hard rail flange to gradually project into the recesses a minimal amount to thereby enhance the gripping capacity of the anchor. This interaction between the two surfaces results in a positive advantage of reducing the relative movement between the anchor and the rail. The percentage of recessed area, as compared to the total bearing pad area, is maintained so that the unit load is distributed over the bearing pad surface. This contact area between the bearing pad surface and rail flange is established predominantly as a surface. In the instant application and for purpose of clarity the relationship between the area of the recesses and total bearing pad area is expressed as a ratio. For maximum gripping efficiency, it has been found that the range of such expressed ratio lies within the limits of 1:20 to 1:2. It is also noted that in the upper limit of the 1:2 ratio, any attempt to increase the recesses area beyond this limit would be detrimental to the rail flange since the unit pressure load would be applied to a bearing area having more recesses than the bearing pad surface, and thus, the bearing pad surface would function as a projection instead of a surface, which would tend to damage the rail flange surface. I-Ieretofore, positive projection means, such as knurling, serrations, etc., have been provided on bearing pad surfaces to enhance the gripping capacity of the anchor. However, such deliberate attempts to provide pronounced, definite projecting means to increase the gripping ca pacity has resulted in rail anchors which seriously mar the flange surface.

Testing results indicate that the instant anchor, with recesses in the bearing pad surface, develops a greater holding capacity of a magnitude of up to 25% greater than that of anchors formed without such recesses.

It is thus seen that the proposed anchor provides a novel and improved bearing surface configuration which increases the holding capacity of the anchor. It is understood that the preferred embodiment is exemplary and that other modifications and variations may be utilized which would fall within the scope and intent of this invention.

I claim:

1. A one piece rail anchor adapted to be secured to the flanges of a rail base comprising:

a. a hook portion at one end of said anchor, said hook portion having an upper and lower jaw adapted to grip one flange of a rail;

b. a central portion extending from said hook portion beneath the rail and beyond the other flange of the rail;

c. shoulder means on the other end of said anchor adapted to retain the other flange of the rail; and,

d. a bearing pad surface on each of said upper and lower jaws, and, a bearing pad surface in proximity to said shoulder, at least one of said bearing pad surfaces having a plurality of recesses therein forming a recessed area wherein the ratio of the recessed area to the total bearing pad area is within the range of 1:20 to 1:2 to thereby cause an interaction between the rail flange and bearing pad surface to increase the gripping capacity of said anchor, said recesses being substantially equally spaced from each other along the length and width of the bearing pad.

2. A rail anchor as defined in claim 1 wherein said anchor is of U-shaped cross-sectional configuration which is substantially maintained throughout the profile of the anchor.

bowed to thereby abut a portion of a cross tie.

6. A rail anchor as defined in claim 1 wherein said anchor is of U-shaped cross-sectional configuration comprising a base in contact with the rail flanges, and, a leg extending from each side of base, said legs being substantially parallel and extending outwardly from said rail. 

1. A one piece rail anchor adapted to be secured to the flanges of a rail base comprising: a. a hook portion at one end of said anchor, said hook portion having an upper and lower jaw adapted to grip one flange of a rail; b. a central portion extending from said hook portion beneath the rail and beyond the other flange of the rail; c. shoulder means on the other end of said anchor adapted to retain the other flange of the rail; and, d. a bearing pad surface on each of said upper and lower jaws, and, a bearing pad surface in proximity to said shoulder, at least one of said bearing pad surfaces having a plurality of recesses therein forming a recessed area wherein the ratio of the recessed area to the total bearing pad area is within the range of 1:20 to 1:2 to thereby cause an interaction between the rail flange and bearing pad surface to increase the gripping capacity of said anchor, said recesses being substantially equally spaced from each other along the length and width of the bearing pad.
 2. A rail anchor as defined in claim 1 wherein said anchor is of U-shaped cross-sectional configuration which is substantially maintained throughout the profile of the anchor.
 3. A rail anchor as defined in claim 2 wherein said bearing pad surfaces are of substantially rectangular configuration.
 4. A one piece rail anchor as defined in claim 3 wherein all of said bearing pad surfaces have a plurality of recesses therein.
 5. A rail anchor as defined in claim 4 wherein the central portion of said anchor is generally downwardly bowed to thereby abut a portion of a cross tie.
 6. A rail anchor as defined in claim 1 wherein said anchor is of U-shaped cross-sectional configuration comprising a base in contact with the rail flanges, and, a leg extending from each side of base, said legs being substantially parallel and extending outwardly from said rail. 